Stable stdlib core

Small, practical, and gated.

The current stable-candidate modules are documented by ownership rules, failure behavior, platform notes, and Windows/Linux x64 native smoke gates.

Stable Candidates

Module	Role	Gate
`std`	Common prelude helpers	Stable import smoke
`io`	Files, directories, paths, streams, process helpers	Native IO/path/process smoke
`str`	Search, slice, trim/case, replace, repeat, parse, padding	Native string smoke plus empty-replace edge
`math`	Integer, float, aggregate, interpolation, trig helpers	Native math smoke plus divmod/smoothstep/atan2 edges
`time`	Clock, sleep, UTC/local date formatting	Native clock/sleep/date smoke
`vec`	Type-erased vectors and typed convenience wrappers	Native vector smoke plus reserve/fill guards
`arena`	Bump allocation, mark/release, wrapped buffers	Native arena smoke plus alignment/release guards

Returned strings are usually heap allocated; callers own non-null results.
File, vector, and arena handles are explicit resources and should be closed or freed.
Mutating resource functions return 0 on success and -1 on invalid handles, invalid arguments, or allocation failure.
Allocating functions return null on allocation failure.
Arena wrapped buffers remain caller-owned; freeing the arena handle does not free the external buffer.
Runtime-backed helpers must state whether they use direct native lowering, host runtime calls, process-backed fallback, or unsupported stubs.

Windows:

powershell -ExecutionPolicy Bypass -File .\tests\conformance\run-native-smoke.ps1

Linux or WSL:

bash tests/conformance/run-native-smoke.sh ./TezzNative-language/bin/tezzc-linux-x64

The focused stdlib edge fixtures are stdlib_math_edges.tn and stdlib_collections_edges.tn.